* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter 15 The Lymphatic System and Immunity
Survey
Document related concepts
Monoclonal antibody wikipedia , lookup
Molecular mimicry wikipedia , lookup
Hygiene hypothesis wikipedia , lookup
Lymphopoiesis wikipedia , lookup
Immune system wikipedia , lookup
Polyclonal B cell response wikipedia , lookup
Adaptive immune system wikipedia , lookup
Immunosuppressive drug wikipedia , lookup
Cancer immunotherapy wikipedia , lookup
Adoptive cell transfer wikipedia , lookup
Transcript
Chapter 15 The Lymphatic System and Immunity Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Lymphatic System • Lymph—fluid in the tissue spaces that carries protein molecules and other substances back to the blood • Lymphatic vessels permit only one way movement of lymph 2 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 3 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 4 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 5 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Lymphatic System • Lymph nodes – Filter lymph – Located in clusters along the pathway of lymphatic vessels – Lymphoid tissue—mass of lymphocytes and related cells inside a lymphoid organ; provides immune function and development of immune cells – Lymph nodes and other lymphoid organs have functions that include defense and WBC formation 6 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 7 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 8 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 9 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Lymphatic System • Thymus – Plays a vital and central role in immunity – Produces T lymphocytes or T cells – Secretes hormone called thymosin – Lymphoid tissue is largely replaced by fat in the process called involution 10 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Lymphatic System • Tonsils – Composed of three masses of lymphoid tissue around the openings of the mouth and throat • Palatine tonsils (“the tonsils”) • Pharyngeal tonsils (adenoids) • Lingual tonsils – Subject to chronic infection – Enlargement of pharyngeal tonsils may impair breathing 11 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 12 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Lymphatic System • Spleen – Largest lymphoid organ in body – Located in upper left quadrant of abdomen – Often injured by trauma to abdomen – Surgical removal called splenectomy – Functions include phagocytosis of bacteria and old RBCs; acts as a blood reservoir – Splenomegaly—enlargement of the spleen 13 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Immune System • Protects body from pathological bacteria, foreign tissue cells, and cancerous cells • Made up of defensive cells and molecules • Nonspecific immunity – Skin—mechanical barrier to bacteria and other harmful agents 14 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Immune System • Nonspecific immunity – Tears and mucus—wash eyes and trap and kill bacteria – Inflammation attracts immune cells to site of injury, increases local blood flow, increases vascular permeability; promotes movement of WBCs to site of injury or infection 15 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Immune System • Specific immunity— • ability of body to recognize, respond to, and remember harmful substances or bacteria • Inherited or inborn immunity—inherited immunity to certain diseases from time of birth 16 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 17 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Immune System • Acquired immunity – Natural immunity—exposure to causative agent is not deliberate • Active—active disease produces immunity • Passive—immunity passes from mother to fetus through placenta or from mother to child through mother’s milk 18 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. The Immune System • Acquired immunity – Artificial immunity—exposure to causative agent is deliberate • Active—vaccination results in immunity • Passive—protective material developed in another individual’s immune system and given to previously nonimmune individual 19 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Molecules • Antibodies- proteins that are part of body Combining sites attach antibodies to specific antigens (foreign proteins-attack body), forming antigen-antibody complex—called humoral or antibody-mediated immunity – Antigen-antibody complexes may: • Neutralize toxins • Clump or agglutinate enemy cells • Promote phagocytosis 20 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 21 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Molecules • Complement proteins-helpers – Group of proteins normally present in blood in inactive state – Complement cascade • Important mechanism of action for antibodies – Complement-binding sites on antibody are exposed after attaching to antigen – Complement triggers a series (cascade) of reactions that produce tiny protein rings that create holes in the surface of a foreign cell 22 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Molecules • Complement proteins – Complement cascade • Ultimately causes cell lysis by permitting entry of water through a defect created in the plasma membrane of the foreign cell – Complement proteins play many other roles in immunity, including the inflammatory response 23 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 24 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Cells • Phagocytes – Types • Neutrophils—short-lived phagocytic cells • Monocytes—develop into phagocytic macrophages and migrate to tissues (Figure 15-15) • Dendritic cells (DCs)—often found at or near external surfaces 25 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Cells • Phagocytes-eater cells – Ingest and destroy foreign cells or other harmful substances via phagocytosis – Macrophages and DCs-on skin act as antigen-presenting cells (APCs) by displaying ingested antigens on their outer surface to trigger specific immune cells 26 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Cells • Lymphocytes – Most numerous of immune system cells – Development of B cells—primitive stem cells migrate from bone marrow and go through two stages of development 27 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Cells • Lymphocytes – Development of B cells-start before birth in bone marrow (stem cells) – After they mature, inactive B cells migrate chiefly to lymph nodes 28 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Cells – Development of B cells • Second stage—activated B cell – contact with antigens, bind to antibodies, plus signal chemicals from T cells – B cell then divides and forms two clones of cells— plasma (effector) cells and memory cells – Plasma cells secrete antibodies into blood; memory cells are stored in lymph nodes – With re-exposure to antigen-memory cells become plasma cells and secrete antibodies 29 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Cells – Function of B cells—indirectly, B cells produce humoral immunity • Activated B cells develop into plasma cells • Plasma cells secrete antibodies into the blood • Circulating antibodies produce humoral immunity 30 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Cells – Development of T cells—stem cells from bone marrow migrate to thymus gland • First stage—stem cells develop into T cells – Occurs in thymus during few months before and after birth – T cells migrate chiefly to lymph nodes • Second stage—T cells develop into activated T cells – antigen binds to T cell’s surface proteins and chemical signal received from another T cell – As with B cells, clones made up of effector cells and memory cells are formed 31 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Cells – Functions of T cells—produce cell-mediated immunity • Cytotoxic T cells—kill infected or tumor cells by releasing a substance that poisons infected or tumor cells • Helper T cells—release chemicals that attract and activate macrophages to kill cells by phagocytosis; produce chemicals that help activate B cells • Regulatory T cells—release chemicals to suppress immune responses 32 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Hypersensitivity of the Immune System • Inappropriate or excessive immune response • Allergy—hypersensitivity to harmless environmental antigens (allergens) – Immediate allergic responses usually involve humoral immunity – Delayed allergic responses usually involve cell-mediated immunity 33 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Hypersensitivity of the Immune System • Autoimmunity—inappropriate, excessive response to self-antigens – Causes autoimmune diseases – Systemic lupus erythematosus (SLE)— chronic inflammatory disease caused by numerous antibodies attacking a variety of tissues 34 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Hypersensitivity of the Immune System • Isoimmunity—excessive reaction to antigens from another human – May occur between mother and fetus during pregnancy – May occur in tissue transplants (causing rejection syndrome) 35 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Deficiency • Congenital immune deficiency or immunodeficiency (rare) – Results from improper lymphocyte development before birth – Severe combined immune deficiency (SCID)—caused by disruption of stem cell development 36 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. Immune System Deficiency • Acquired immune deficiency – Develops after birth – Acquired immunodeficiency syndrome (AIDS)—caused by HIV infection of T cells 37 Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc.